FIELD OF THE INVENTION
The invention relates to a blade-hub linkage device with laminate attachment, intended to fasten a rotor blade, preferably fitted from the outset with such an attachment, to a hub of a variable-pitch multiblade rotor, which can be used, preferably as a tail rotor, in particular a ducted tail rotor, for an aircraft such as a helicopter.
The invention also relates to a variable-pitch multiblade ducted tail rotor for a helicopter, as well as to a blade provided with a laminate attachment, and particularly intended for equipping a rotor according to the invention.
The blade according to the invention, of the type held to the hub by the inner radial end (with respect to the axis of the hub) of at least one twistable and preferably also flexible blade attachment composite bundle or torsion bar, and known by Patents U.S. Pat. Nos. 4,626,172 and 4,892,462, comprises
a rigid shell with aerodynamic profile, extended on the side intended to point toward the hub by a tubular blade root, PA1 a strengthened framework, which is at least partially housed substantially longitudinally in the shell, and PA1 a rooting part of the blade, comprising at least one bar for attachment of the blade, which is elongated substantially in the longitudinal extension of the shell, said bar being twistable about its longitudinal axis, made from composite material and comprising substantially unidirectional fibers which are agglomerated by a rigidified synthetic resin, said bar being linked to the said framework and extending at least partially outside the shell, passing through the blade root. PA1 a drive shaft, intended to be driven in rotation about an axis of rotation of the rotor, PA1 a hub linked in rotation with the drive shaft, PA1 a plurality of blades, each of which is joined to the hub by a rooting part with at least one composite, elongate torsion bar,
The torsion property of the elongate composite bar allows control of the pitch of the blade by twisting the bar about its longitudinal axis, and its property of being preferably also flexible allows angular oscillations of flapping and in drag of the blade.